Monoazo dyes containing at least one sulfo group and at least two basic or cationic groups

ABSTRACT

Compounds of the formula ##STR1## wherein F is the residue of a monoazo or disazo compound, each X is independently --NR 2  --Q--NR 3  R 4  or --NR 2  --Q--N.sup.⊕ R 5  R 6  R 7 , 
     wherein Q is linear or branched C 2-6  alkylene, R 2  is hydrogen or C 1-4  alkyl, 
     each of R 3 , R 4 , R 5  and R 6  is independently hydrogen; C 1-6  alkyl; C 2-6  alkyl substituted by hydroxy or cyano; C 1-3  alkyl substituted by phenyl or substituted phenyl having 1 to 3 substituents selected from chloro, C 1-4  alkyl and C 1-4  alkoxy; C 5-6  cycloalkyl or C 5-6  cycloalkyl substituted by 1 to 3 C 1-4  alkyl groups, with the proviso that neither R 5  and R 6  can be hydrogen, or 
     R 3  and R 4  or R 5  and R 6  taken together and with the nitrogen atom to which they are joined from a 5- or 6-membered ring containing at most one further hetero atom, and 
     R 7  is C 1-4  alkyl or benzyl, 
     each Z 1  is independently --CO--, --SO 2  -- or ##STR2## wherein R 1  is hydrogen or C 1-4  alkyl, and Y is chloro, hydroxy, amino or an aliphatic or aromatic amino group, 
     each Z 2  is independently ##STR3## wherein R 1  is hydrogen or C 1-4  alkyl, m is 1 or 2, 
     n is 0-4, and 
     p is 0-3, 
     with the proviso that n+2p≧m+1, 
     are useful as dyes for paper, leather and cellulosic fibres.

This application is a division of application Ser. No. 31,781, filedApr. 20, 1979 and now U.S. Pat. No. 4,273,707.

This invention relates to azo dyes containing sulphonic acid groups andalso basic and/or cationic groups.

The invention provides compounds of formula I ##STR4## in which F is theresidue of a mono- or dis-azo compound; each Z₁, independently, is adivalent group of formula --CO--, --SO₂ -- or ##STR5## in which Y is Cl,OH, NH₂ or an aliphatic or aromatic amino group, and R₁ is hydrogen orC₁₋₄ alkyl;

each Z₂, independently, is a trivalent group of the formula ##STR6## inwhich R₁ is as defined above; each X, independently, is a basic group--NR₂ --Q--NR₃ R₄ or a cationic group --NR₂ --Q--N.sup.⊕ R₅ R₆ R₇,

in which R₂ is hydrogen or C₁₋₄ alkyl,

Q is linear or branched C₂₋₆ alkylene,

R₃ and R₄ are independently hydrogen, unsubstituted C₁₋₆ alkyl, C₂₋₆alkyl substituted by hydroxy or CN, C₁₋₃ alkyl substituted by phenylwhich is unsubstituted or substituted by up to 3 substituents selectedfrom chlorine, C₁₋₄ alkyl, C₁₋₄ alkoxy or C₅₋₆ cycloalkyl unsubstitutedor substituted by up to 3 C₁₋₄ alkyl groups

or R₃ and R₄, together with the N atom to which they are attached, forma 5- or 6-membered saturated heterocyclic ring, which may contain onefurther hetero atom,

R₅ and R₆ may independently have any of the above significances of R₃and R₄ other than hydrogen,

R₇ is C₁₋₄ alkyl or benzyl;

m is 1 or 2

n is 0 or an integer from 1 to 4

p is 0 or an integer from 1 to 3

whereby (n+2p)≦m+1.

In the compounds of formula I, the m sulphonic acid groups may reactwith x groups to form internal salts of the type (XH).sup.⊕ SO₃.sup.⊖ orX.sup.⊕ SO₃.sup.⊖. The compounds of formula I have more basic and/orcationic groups than sulphonic acid groups, and the additional basicand/or cationic groups may form external salts, thus rendering thecompounds water-soluble.

In the residue of a mono- or dis-azo compound represented by F, thediazo component may belong to the aromatic carbocyclic or aromaticheterocyclic series, as for example the aniline, aminonaphthalene,aminodibenzofuran or benzothiazolylaminophenyl series, the anilineseries being preferred. The terminal coupling component preferablybelongs to the naphthalene series, and is preferably derived from1-naphthol-3- or -4-sulphonic acid or a derivative thereof, particularly6-amino-1-naphthol-3-sulphonic acid or a derivative formed by reactionat the amino group thereof.

In residues of disazo compounds, the central component radicalpreferably belongs to the phenylene, naphthylene ortetrahydronaphthylene series, more preferably the 1,4-phenylene series.

F may also for example be the residue of a disazo compound in which thecoupling component radicals or diazo component radicals of two monoazocompounds are connected together directly or through a bridging group.

The sulphonic acid groups may be located in the diazo and/or in thecoupling component radical and optionally also in the central componentradical or bridging group. Preferably, however, the coupling componentradical carries at least one sulphonic acid group, more preferably oneonly.

The (n+2p) X groups, which may be the same or different, are connectedthrough the polyvalent groups Z₁ and Z₂ to the diazo component radicaland/or the terminal coupling component radical of the group F. Where Z₁is Z₁ ', i.e. --CO-- or --SO₂ --, then the group --Z₁ '--X (forconvenience referred to as X_(I)) is preferably located on the diazocomponent radical. For a diazo component radical of the aniline series,two groups X_(I) are preferably attached as in formula IIa or IIb##STR7## in which the groups X_(I) are preferably identical, andpreferably there is no, or only one, further substituent on the benzenering.

The groups --Z₁ "--X or ##STR8## together represented for convenience asX_(II), in which Z₁ " is the divalent group ##STR9## are preferablylocated on the diazo component radical and/or the terminal couplingcomponent radical, it being particularly preferred that the lattercontains at least one such group. For a diazo component radical of theaniline series, formulae IIIa and IIIb are preferred. ##STR10## Informula IIIa, one further substituent may be located preferably at the2-, 4- or 6-position or two further may be located preferably at the2,5-positions. In formula IIIb there is preferably one additionalsubstituent, which may be in any position.

When the terminal coupling component radical carries a group X_(II),this is preferably derived from a compound of formula IV ##STR11## inwhich the arrow shows the position at which coupling occurs.

The alkylene group Q is preferably linear and more preferably is anethylene or propylene group.

When groups R₁ and R₂ are alkyl, they are preferably methyl. R₁ and R₂are preferably R₁ ' and R₂ ', where R₁ ' and R₂ ' are independentlymethyl or hydrogen, more preferably hydrogen.

The groups R₃ and R₄ are preferably identical. When they are C₁₋₆ alkylgroups, they may be straight-chain or branched and are preferably C₁₋₄alkyl, more preferably methyl or ethyl. Cyano- and hydroxy-substitutedC₂₋₆ alkyl groups are preferably substituted ethyl are propyl in whichthe substituent is other than at the α-position. When R₃ and R₄ arephenylalkyl, they are preferably benzyl, the phenyl group beingpreferably unsubstituted. When R₃ and R₄ are cycloalkyl, they arepreferably cyclohexyl; where the cyclohexyl is alkyl substituted, thesubstituents are preferably methyl. Where R₃ and R₄, together with thenitrogen atom to which they are attached, form a heterocyclic ring, thisis preferably a pyrrolidine, piperidine or morpholine ring.

Preferably R₃ and R₄ are R₃ ' and R₄ ' where R₃ ' and R₄ ' areindependently hydrogen, linear or branched C₁₋₆ alkyl, linear hydroxyC₂₋₃ alkyl or benzyl, or together with the N atom form a pyrrolidine,piperidine or morpholine ring. More preferred significances are R₃ " andR₄ ", which are independently hydrogen, linear or branched C₁₋₄ alkyl orhydroxyethyl, or together with the N atom form a piperidine ormorpholine ring. Particularly preferred significances of R₃ and R₄ areR₃ ''' and R₄ ''', where R₃ ''' and R₄ ''' are independently methyl orethyl.

Groups R₅ and R₆ are also preferably identical, and the preferredsignificances given above for R₃ and R₄ apply equally to R₅ and R₆,except that R₅ and R₆ may not be hydrogen.

Where R₇ is alkyl it is preferably methyl or ethyl, more preferablymethyl. R₇ is preferably R₇ ' where R₇ ' is methyl, ethyl or benzyl,particularly methyl.

Where X is a basic group --NR₂ --Q--NR₃ R₄,

it is preferably X_(a) =--NR₂ --Q--NR₃ R₄ ;

more preferably X_(b) =--NR₂ '--Q--NR₃ "R_(4";)

still more preferably X_(c) =--NR₂ '--(CH₂)₂₋₆ --NR₃ "R₄ ";

particularly X_(d) =--NR₂ '--(CH₂)₂ or 3 --NR_(3'''R) ₄ ''',

in which R₂ ' is preferably hydrogen.

Where X is a cationic group --NR₂ --Q--N.sup.⊕ R₅ R₆ R₇, then thepreferred significances are as X_(a) -X_(d) above in which R₅ and R₆ areas R₃ and R₄, and R₇ is R₇ '. Particularly preferred is the group

X_(e) =--NR₂ '--(CH₂)₂ or 3 --N.sup.⊕ (CH₃)₃.

Where X is a cationic group the corresponding anion is either a--SO₃.sup.⊖ group in the molecule or an external anion A.sup.⊖. Thenature of A.sup.⊖ is not critical; it should however benon-chromophoric. Examples of suitable anions A.sup.⊖ are chloride,bromide, iodide, methanesulphonate, ethane sulphonate and hydrogensulphate.

Where Y is an aliphatic amino group, it is preferably a monoalkylaminoor dialkylamino group in which the alkyl groups have 1-4 carbon atoms,may be linear or branched, and may be unsubstituted or substituted byCl, Br, phenyl or, preferably, hydroxy; or Y may be a C₅₋₆cycloalkylamino group. Where Y is an aromatic amino group, it ispreferably an anilino group, which may be unsubstituted or substitutedin the phenyl ring by one or two substituents selected from halogen(preferably chlorine), C₁₋₄ alkyl, C₁₋₄ alkoxy, hydroxy and phenoxy.

Y is preferably Y_(a) where Y_(a) is Cl, OH, NH₂, mono(C₁₋₄)alkylamino,monohydroxy(C₂₋₄)alkylamino, di(C₁₋₂)alkylamino;bis[hydroxy(C₂₋₄)alkyl]amino or anilino. More preferably Y is y_(b)where y_(b) is Cl, OH or anilino.

As stated above, X_(I) signifies --CO--X or --SO₂ X, and X_(II)signifies ##STR12##

Preferred significances of the groups X_(I) are, independently,

x_(Ia) =--CO--X_(a) or --SO₂ --X_(a) ;

more preferably X_(Ib) =--CO--X_(b) or --SO₂ --X_(b) ;

still more preferably X_(Ic) =--CO--X_(c)

and particularly X_(Id) =--CO--X_(d), in which R₂ ' is preferablyhydrogen.

This order of preferences applies also for cationic groups, in whichhowever X_(I) is most preferably X_(Ie) where X_(Ie) is --CO--X_(e).

Preferred significances of the groups X_(II) are, independently,##STR13## where T is X_(a) or Y_(a), in which Y_(a) is more preferablyY_(b) ;

more preferably ##STR14## still more preferably ##STR15## andparticularly ##STR16## in which R₁ ' and R₂ ' are preferably hydrogen.

This order of preferences applies also for cationic groups, in whichhowever X_(II) is most preferably X_(IIe), where X_(IIe) is ##STR17##

A group of preferred compounds of formula I are those of formula Ia##STR18## in which the groups X_(Ia) are identical or differentpreferably identical,

R₈ is hydrogen, C₁₋₄ alkyl, C₁₋₄ alkoxy, halogen, mono(C₁₋₄ alkyl)amino,di(C₁₋₄ alkyl)amino, --SO₂ NR₁ R₁ or --CONR₁ R₁, where R₁ is as definedabove;

R₁₁ is hydrogen, halogen (preferably chlorine), C₁₋₄ alkyl, C₁₋₄ alkoxy,--NHCO--(C₁₋₄ alkyl), --NHCONH₂, --NHCO(CH₂)₁₋₃ N(C₁₋₄ alkyl)₂ or--NHCO(CH₂)₁₋₃ N.sup.⊖ (CH₃)₃ A.sup.⊕ where A.sup.⊕ is an anion;

R₁₂ is hydrogen, C₁₋₄ alkyl or C₁₋₄ alkoxy;

R₁₃ is hydrogen, NH₂, (C₁₋₄ alkyl)carbonylamino, benzoylamino whosephenyl ring may be substituted with up to 2 substituents selected fromhalogen, NO₂, NH₂, C₁₋₄ alkyl and C₁₋₄ alkoxy, or ##STR19## where R₁ andY are as defined above and Y' has any significance of Y other than Cl;

and q is 0 or 1.

R₈ is preferably R₈ ' where R₈ ' is hydrogen, methyl, methoxy orchlorine, more preferably hydrogen.

In the group ##STR20## the phenylene linkages may be in the 1,3- or1,4-positions; preferably the group has the structure ##STR21##

R₁₁ is preferably R₁₁ ' where R₁₁ ' is hydrogen, methyl or methoxy.

R₁₂ is preferably R₁₂ ' where R₁₂ ' is hydrogen, methyl or methoxy.

R₁₃ is preferably R₁₃ ' where R₁₃ ' is hydrogen, NH₂, acetylamino orunsubstituted benzoylamino.

Preferred compounds of formula Ia are those in which

(1) X_(Ia) is X_(Ib), more preferably X_(Ic) and particularly X_(Id) orX_(Ie)

(2) R₈ is R₈ ', particularly hydrogen

(3) the group ##STR22## (4) R₁₃ is R₁₃ ', and (5) the X_(I) groups arein the 2,5- or 3,5-positions, counting from the carbon atom bearing theazo group.

Another group of preferred compounds of formula I are those of formulaIb ##STR23## in which the basic or cationic groups may be the same ordifferent and are preferably located at the positions indicated informulae IIIa, IIIb and/or IV above,

R₉ is hydrogen, halogen, C₁₋₄ alkyl, C₁₋₄ alkoxy, phenoxy, --NHCOR₁₄,--SO₂ R₁₄, --SO₂ NR₁ R₁ or --CONR₁ R₁, where R₁ is as defined above, inwhich R₁₄ is C₁₋₄ alkyl or phenyl;

R₁₀ is hydrogen, halogen, C₁₋₄ alkyl or C₁₋₄ -alkoxy;

r is 0 or 1;

and R₁₁, R₁₂, R₁₃, Z₁ ", Z₂, X_(a), m, n, p and q are as defined above.

Preferably R₉ is R₉ ' where R₉ ' is hydrogen, chlorine, methyl, methoxy,acetylamino, benzoylamino, --SO₂ NH₂ or --CONH₂. More preferably it isR₉ ", where R₉ " is hydrogen, chlorine, methyl, methoxy, acetylamino orbenzoylamino, particularly hydrogen.

R₁₀ is preferably R₁₀ ' where R₁₀ ' is hydrogen, chlorine, methyl ormethoxy, particularly hydrogen.

Preferably R₁₁, R₁₂ and R₁₃ are, independently, R₁₁ ', R₁₂ ' and R₁₃ '.The group R₁₃ is preferably in position 6. If r=0, then preferably a--Z₁ "--X_(a) or --Z₂ --(X_(a))₂ group occupies position 6. Preferablym=1, and in this case the sulpho group is in position 3 or 4, preferablyin position 3.

Preferred compounds of formula Ib are those in which, independently,

(1) R₉ is R₉ ', more preferably R₉ ", particularly hydrogen,

(2) R₁₀ is R₁₀ ', particularly hydrogen,

(3) the group ##STR24## (4) R₁₃ is R₁₃ ' in position 6, or (5) r=0, anda basic or cationic group is in position 6

(6) the groups X_(a) are preferably X_(b), more preferably X_(c),particularly X_(d) or X_(e),

(7) m=1 and the sulpho group is in position 3.

More preferred compounds of formula Ib are those of formula Ic ##STR25##in which X_(IIb) and R₉ ' are as defined above.

Particularly preferred compounds of formula Ic are those in which,independently,

(1) R₉ ' is R₉ ", particularly hydrogen,

(2) X_(IIb) is X_(IIc), more preferably X_(IId) or X_(IIe),

and (3) R₁₁ ' and R₁₂ ' are hydrogen.

A further group of more preferred compounds of formula Ib are those offormula Id ##STR26## particularly those in which, independently, (1) R₉' is R₉ " and R₁₀ ' is hydrogen,

(2) X_(IIb) is X_(IIc), more preferably X_(IId) or X_(IIe),

(3) R₁₁ ' and R₁₂ ' are hydrogen,

and (4) q=1.

Other groups of preferred compounds of formula I are those of formula Ie##STR27## wherein the groups X_(Ia) are preferably identical, and Z₃ isa divalent N-containing bridging group.

The variables in the two parts of the molecule connected by Z₃ may bethe same or different but are preferably the same.

Z₃ is preferably Z_(3a) where Z_(3a) is --NH--; --NHCONH--; ##STR28## inwhich Y is as defined above and is preferably Y_(c) where Y_(c) is Cl,NH₂ or --NH--phenyl; ##STR29## containing a 1,3- or 1,4-phenylene group;--NHCOCH₂ CH₂ CONH--; or --NHCOCH═CHCONH--. More preferably it is Z_(3b)where Z_(3b) is --NHCONH--; ##STR30## --NHCOCH₂ CH₂ CONH-- or--NHCOCH═CHCONH--; particularly preferred is Z_(3c), i.e. --NHCONH--,##STR31##

Preferred compounds of formula Ie are those in which, independently,

(1) R₈ is R₈ ', particularly hydrogen,

(2) X_(Ia) is X_(Ib), more preferably X_(Ic) and particularly X_(Id) orX_(Ie),

(3) Z₃ is Z_(3a), preferably Z_(3b), particularly Z_(3c),

(4) Groups X_(Ia) are in the 2,5- or 3,5-positions with respect to thecarbon atom bearing the azo group.

A further group of preferred compounds of formula I are those of formulaIf ##STR32##

in which R₉ ', X_(IIb) and Z₃ are as defined above, and X_(IIb)preferably occupies the positions shown in formulae IIIa and b. Thevariables in the two parts of the molecule joined by bridging group Z₃may be the same or different but are preferably the same.

Preferred compounds of formula If are those in which, independently,

(1) R₉ ' is R₉ ", particularly hydrogen,

(2) X_(IIb) is X_(IIc), particularly X_(IId) or X_(IIe),

(3) Z₃ is Z_(3a), more preferably Z_(3b), particularly Z_(3c),

(4) the sulpho group is in position 3, the bridging group Z₃ is inposition 6 and both parts of the molecule joined by Z₃ are identical.

A still further preferred group of compounds of formula I have formulaIg ##STR33## in which the bridging group Z₄ is 1,3- or 1,4-phenylene ora group of formula ##STR34## where R₁₅ is hydrogen, chlorine, methyl ormethoxy, particularly hydrogen

and Z₅ is a direct bond, --(CH₂)_(t) ---, --O--, --O(CH₂)_(t) O--, --SO₂--, --NHCO--, --NHCONH--, --NHCO(CH₂)_(t) CONH-- or --CONH(CH₂)_(t)NHCO--, where t is 2 or 3, preferably 2.

The two parts of the molecule joined by Z₄ may be identical or differentbut are preferably identical.

Z₄ is preferably Z_(4a) where Z_(4a) is 1,3- or 1,4-phenylene, ##STR35##

Preferred compounds of formula Ig are those in which

(1) X_(IIb) is X_(IIc), particularly X_(IId) or X_(IIe),

(2) Z₄ is Z_(4a),

and (3) the sulpho group is in position 3, the group X_(IIb) in position6, and the two parts of the molecule are identical.

The invention also provides a process for the preparation of compoundsof formula I, comprising the step of coupling to a correspondingterminal coupling component a corresponding diazotised amine ormonoazoamine, the necessary n (--Z₁ --X) and/or ##STR36## groups beingalready present in the coupling component and/or the diazo component.

Compounds of formula I containing X_(II) groups, for example compoundsof formula Ib, Ic, Id, If or Ig, may also be prepared by reacting acompound of formula V ##STR37##

in which Hal is halogen, particularly chlorine, in any desired orderwith n+2p moles of a diamine of formula VIa and/or formula VIb

    HNR.sub.2 --Q--NR.sub.3 R.sub.4                            VIa

    [HNR.sub.2 --Q--N.sup.⊕ R.sub.5 R.sub.6 R.sub.7 ]A.sup.⊖VIb

and optionally with n moles of a compound HY'.

In all the above definitions, the term "halogen" signifies fluorine,chlorine or bromine.

The processes, of which the former is preferred, are carried out inconventional manner. Thus the coupling reaction may be carried out inweakly acid or weakly alkaline aqueous media, and the products may beisolated and purified in known manner.

The compounds of formula I may be transformed into water-soluble saltforms by treating the basic compounds with at least a stoichiometricquantity of an organic or inorganic acid. In the compounds of formula I,free basic (i.e. non-protonated) X groups may also be treated withalkylating agents containing the group R₇ to give quaternaryammonium-containing cationic X groups.

The starting diazo and coupling components are either known or can beobtained from available starting materials by known or analogousprocesses. Thus, for example, the diazo components containing groupsX_(I) for the compounds of formula Ia or Ie may be prepared by reactionof the corresponding nitrophenylcarboxylic acid chloride or nitrophenylsulphonylchloride with stoichiometric amounts of one or more diamines offormula VIa and/or VIb and finally reducing the nitro group to an aminogroup.

The diazo components containing group X_(II) for the compounds offormulae Ib, Ic and If may for example be prepared by reaction ofcyanuric halide with an optionally substituted nitroaniline, a diamineof formula VIa and/or VIb and optionally a compound HY' in any desiredorder, and finally reducing the nitro group.

Similarly, the group X_(II) -containing coupling components forcompounds of formula Ib, Id or Ig may be obtained by condensing acyanuric halide with the corresponding amino-containing couplingcomponent, diamine of formula VIa and/or VIb and optionally compound HY'in any desired order.

Compounds of formula I in the form of their water-soluble acid salts aredyestuffs useful for dyeing or printing substrates consisting of orcontaining cellulosic fibres, for example cotton, or preferably for thedyeing or printing of paper. They may also be used for dyeing orprinting leather, particularly vegetable-tanned low-affinity leather.

Cotton may for example be dyed by an exhaust dyeing process at roomtemperature to the boil, or printed with printing pastes of conventionaltype. Sized or unsized paper may be printed or dyed in the mass duringthe manufacturing process, or by the dipping process. Leather may bedyed in conventional manner.

Compounds of formula I may also be used in the form of liquid or soliddye compositions. They may be produced in the form of stable liquid,preferably aqueous, compositions by known methods, preferably bysolution in a suitable solvent, optionally in the presence of anauxiliary, for example a stabiliser. Such compositions may for examplebe prepared as disclosed in French Pat. No. 1,572,030. A suitable liquidcomposition is for example the following (parts are by weight):

100 parts compound of formula I as acid salt

1-100, preferably 1-10, parts inorganic salt

1-100 parts of an organic acid, e.g. formic, acetic, lactic or citricacid

100-800 parts water

0-500 parts of a solubilising agent, for example glycols such asdiethylene, triethylene or hexylene glycol; glycol ethers such as methylcellosolve, methyl carbitol, butylpolyglycol; urea; formamide;dimethylformamide, etc.

The compounds of formula I may also be prepared in solid, preferablygranular, form, preferably by granulating as described in French Pat.No. 1,581,900. A suitable solid composition is for example the following(parts are by weight):

100 parts compound of formula I as acid salt

1-100, preferably 1-10, parts inorganic salt

0-800 parts of a filler, preferably a nonionic material such as dextrin,sugar, glucose or urea.

The solid compositions may contain up to 10% residual moisture.

The dyestuffs of formula I, in the form of their acid salts, have goodsolubility properties, particularly good solubility in cold water. Whenused in paper-making, they colour the waste water only slightly or notat all, which is desirable for ecological reasons. They do not givemottling of the dyed paper and are insensitive to pH over wide ranges.The resulting dyeings on paper are brilliant and are characterised bygood light-fastness; after long illumination the shades changetone-to-tone. The dyed paper is fast not only to water but also to milk,fruit juices and sweetened mineral water; because of the good alcoholfastness of the dyes (particularly those of formulae Ic, If and Ig), itis also resistant to alcoholic drinks.

The dyes exhibit high substantivity, that is they exhaust practicallyquantitatively on the substrate. They may be added to the paper massdirectly in the form of a dry powder or granulate, without first makingup a solution, without loss of brilliance or yield. The dyes accordingto the invention may also be used in soft water without loss of yield.

Fibrous materials containing wood pulp are dyed with the dyestuffsaccording to the invention in as good and level quantity as with purelycationic dyes.

The dyed paper is both oxidatively and reductively bleachable, which isimportant for the recycling of waste paper.

The following Examples, in which solid materials are given as parts byweight and liquids as parts by volume, all percentages are weightpercentages and temperatures are in degrees Centigrade, illustrate theinvention.

PREPARATION OF STARTING MATERIALS Example (a)

106 Parts 5-nitroisophthalic acid are stirred into 300 partschlorobenzene containing 0.5 part triethylamine and warmed to 80° C.;finally 80 parts thionyl chloride are slowly added dropwise. Afterstirring 3 hours at 80°, the temperature is raised slowly to 120°. Whenall is dissolved, the solution is cooled to 90° and a mixture of 137parts 3-dimethylaminopropylamine and 60 parts chlorobenzene is addeddropwise; finally 53 parts sodium carbonate are added. The resultingsuspension is stirred 2 hours at 100°, cooled and treated with 100 partswater. The mixture is acidified to pH 5 with 30% hydrochloric acid andthe chlorobenzene removed by steam distillation.

The residual aqueous solution is made alkaline, causing the nitroproduce to separate as an oil, which is taken up in ethyl acetate,washed with brine, dried and evaporated to give a brown oil. The oil isdissolved in 200 parts water and 120 parts 30% hydrochloric acid, andthis solution is added dropwise to a hot suspension of 100 parts ironturnings, 100 parts water and 10 parts 30% HCl. After 2 hours at 95°-98°the reduction is complete. Sodium carbonate is added to make the mixturealkaline to brilliant yellow indicator, and the product is filtered hot.The filtrate (˜520 parts by volume) contains 110 parts of the compoundof the formula ##STR38##

Example (b)

If example (a) is repeated using nitroterephthalic acid, the product isthe compound of the formula ##STR39##

Example (c)

92 Parts cyanuric chloride are dissolved in 750 parts acetone and cooledto 0°-5°. 69 Parts 3-nitroaniline are added, then 130 parts of a 4 Nsodium carbonate solution are added dropwise over an hour. The mixtureis stirred for an hour, then 600 parts of ice water are added. Theresulting suspension is filtered and the moist residue is added slowlyin small portions to 250 parts 3-dimethylaminopropylamine. Thetemperature of the mixture rises to 60°-70°, giving a syrupy solutionwhich is stirred for 1 hour at 90°-100° and then diluted to 1000 partsby volume by addition of ice. The aqueous phase is separated off, andthe resinous residue is stirred with 200 parts water and 90 parts 30%HCl, giving an aqueous suspension with a pH of 5.

In a second vessel 300 parts of water, 70 parts iron turnings and 20parts 30% HCl are stirred together for 1 hour. The weakly acidsuspension prepared as above is added, and the temperature is held for 2hours at 95°-98°. The product is made alkaline to brilliant yellow byadding sodium carbonate, and filtered hot. The yellow-brown filtrate(˜950 parts by volume) contains 155 parts of the compound of the formula##STR40##

In place of the 3-nitroaniline, the following nitro compounds may alsobe used to produce corresponding products: 4-nitroaniline, 2-chloro- or2-bromo-4-nitroaniline, 2-methyl-4-nitroaniline,2-methoxy-4-nitroaniline, 2-methyl-3-nitroaniline,4-chloro-3-nitroaniline, 4-methyl-3-nitroaniline,4-methoxy-3-nitroaniline, 2-methyl-5-nitroaniline,2-methoxy-5-nitroaniline and 5-chloro-2-methoxy-3-nitroaniline.

Example (d)

A mixture of water and ice (125 parts each) is stirred with 92 partscyanuric chloride to give a fine dispersion. 130 Parts3-diethylaminopropylamine is added dropwise over 3 hours, at a rate suchthat the temperature does not exceed 5°. The product is stirred for 1hour at 45°-50° and treated with 100 parts 30% caustic soda solution,causing the product to separate as a white mass which is suctionfiltered and washed with water. After drying in vacuum at 60°, 150 partsof 2,4-diamino-N,N'-bis-(3-diethylaminopropyl)-6-chloro-1,3,5-triazineare obtained.

This product is dissolved in 600 parts water and 106 parts 30% HCl, and95 parts 6-amino-1-naphthol-3-sulphonic acid are added followed by 100parts sodium acetate. The mixture is heated to 90°-95°, the pH sinkingfrom 4.5 to 3.7. After 3 hours the reaction is complete, and on coolinga clear brown solution containing 210 parts of the compound of formula##STR41##

The use of alternative diamines in the process of examples a-d gives thecorresponding alternative diazo components or coupling components asshown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                                            reacted with the con-                                                         densation product                                                                        reacted with cyanuric                         reacted with 5-nitro-                                                                    reacted with nitro-                                                                     cyanuric chloride                                                                        chloride and 6-amino-                         isophthalic acid and                                                                     terephthalic acid                                                                       3-nitroaniline                                                                           1-naphthol-3-sulphonic                        reduced gives diazo                                                                      and reduced gives                                                                       and reduced gives                                                                        acid gives the                                                                coupling                   Diamine            component: diazo component:                                                                        the diazo component:                                                                     component:                 __________________________________________________________________________    H.sub.2 N(CH.sub.2).sub.3N(CH.sub.3).sub.2                                                       D.sub.1a (Example a))                                                                    D.sub.1b (Example b))                                                                   D.sub.1c (Example                                                                         K.sub.2d                  H.sub.2 N(CH.sub.2).sub.3N(C.sub.2 H.sub.5).sub.2                                                 D.sub.2a   D.sub.2b  D.sub.2c  K.sub.1d (Example d))      H.sub.2 N(CH.sub.2).sub.2N(CH.sub.3).sub.2                                                        D.sub.3a   D.sub.3b  D.sub.3c   K.sub.3d                  H.sub.2 N(CH.sub.2).sub.2N(C.sub.2 H.sub.5).sub.2                                                 D.sub.4a   D.sub.4b  D.sub.4c   K.sub.4d                   ##STR42##          D.sub.5a   D.sub.5b  D.sub.5c   K.sub.5d                   ##STR43##          D.sub.6a   D.sub.6b  D.sub.6c   K.sub.6d                   ##STR44##          D.sub.7a   D.sub.7b  D.sub.7c   K.sub.7d                   ##STR45##          D.sub.8a   D.sub.8b  D.sub.8c   K.sub.8d                   ##STR46##          D.sub.9a   D.sub.9b  D.sub.9c   K.sub.9d                   ##STR47##         D.sub.10a  D.sub.10b D.sub.10c  K.sub.10d                   ##STR48##         D.sub.11a  D.sub.11b D.sub.11c  K.sub.11d                  H.sub.2 N(CH.sub.2).sub.5N(C.sub.2 H.sub.5).sub.2                                                D.sub.12a  D.sub.12b D.sub.12c  K.sub.12d                  H.sub.2 N(CH.sub.2).sub.6N(CH.sub.3).sub.2                                                       D.sub.13a  D.sub.13b D.sub.13c  K.sub.13d                  H.sub.2 N(CH.sub.2).sub.3N(CH.sub.2 CH.sub.2 OH).sub.2                                           D.sub.14a  D.sub.14b D.sub.14c  K.sub.14d                  __________________________________________________________________________     Diazo components as listed in column 4 but prepared using 4nitroaniline       are designated D.sub.1c' - D.sub.14c' and those prepared using                4methyl-3-nitroaniline are designated D.sub.1c" - D.sub.14c".            

Example 1

24 Parts by volume of the solution prepared as in Example (c) aretreated with 20 parts ice and 3 parts 30% HCl and diazotised with 10parts 1 N sodium nitrite solution at 0°-5°. The diazonium salt solutionis added dropwise to a mixture of 3 parts6-acetylamino-1-naphthol-3-sulphonic acid (K₁) and 100 parts water,maintaining the pH at 7-8 by addition of sodium carbonate solution. Anorange dyestuff suspension is obtained. When no more diazonium salt canbe detected, the suspension is treated with zinc chloride until therun-off of a spot test has become almost colourless. The dyestuff isfiltered off and dried at 80° in a vacuum. The product of the formula##STR49## is obtained in the form of a powder which is easily soluble inweakly acid to acid aqueous media and dyes paper in red-orange tones.The dyed paper has good light- and wet-fastness.

Example 2

If instead of 24 parts of the solution of Example (c), 18 parts of thesolution obtained in Example (a) is used in Example 1, a dyestuff havingthe formula ##STR50## is obtained in the form of a powder which issoluble in acidic aqueous media and gives on paper yellow-orange dyeingshaving good light- and wet-fastness.

Examples 3-27

Following the procedure of Example 1 and using the coupling and diazocomponents listed in Table 2 below, further monoazo dyestuffs can beobtained which dye paper in the colours indicated, with good light- andwet-fastness.

Abbreviations used for colours:

yo=yellow-orange

r=red

brv=brilliant red-violet

or=orange-red

br=brown-red

ro=red-orange

bbr=brilliant bluish-red

bo=brown-orange

bor=bordeaux red

o=orange

blr=bluish-red

v=violet

sr=scarlet red

rv=red-violet

                  TABLE 2                                                         ______________________________________                                        Example                  Diazo                                                No.    Coupling Component                                                                              Component  Colour                                    ______________________________________                                         3     6-benzoylamino-1-naphthol-                                                                      D.sub.1c   ro                                               3-sulfonic acid (K.sub.2)                                               4     1-naphthol-3-sulfonic                                                                           "          ro                                               acid (K.sub.3)                                                          5     1-naphthol-4-sulfonic                                                                           "          ro                                               acid (K.sub.4)                                                          6     K.sub.1           D.sub.1c'  blr                                        7     K.sub.2           "          blr                                        8     K.sub.3           "          blr                                        9     K.sub.4           "          blr                                       10     K.sub.1           D.sub.1c"  r                                         11     K.sub.2           "          r                                         12     K.sub.3           "          r                                         13     K.sub.4           "          r                                         14     K.sub.1           D.sub.2c   ro                                        15     K.sub.2           "          ro                                        16     K.sub.3           "          ro                                        17     K.sub.4           "          ro                                        18     K.sub.1           D.sub.2c'  blr                                       19     K.sub.2           "          blr                                       20     K.sub.3           "          blr                                       21     K.sub.4           "          blr                                       22     K.sub.1           D.sub.1b   ro                                        23a    K.sub.2           D.sub.1a   yo                                        23b    K.sub.2           D.sub.1b   ro                                        24a    K.sub.3           D.sub.1a   yo                                        24b    K.sub.3           D.sub.1b   ro                                        25a    K.sub.4           D.sub.1a   yo                                        25b    K.sub.4           D.sub. 1b  ro                                        26     K.sub.1           D.sub.2a   yo                                        27     K.sub.3           D.sub.2b   yo                                        ______________________________________                                    

Similarly, coupling components K₁ -K₄ can be reacted with any of thediazo components listed in Table 1, to give dyestuffs which give dyeingson paper with good light- and wet-fastness.

Example 28

67 Parts by volume of the solution prepared in Example (a) are treatedwith 50 parts ice and 10 parts 30% HCl and diazotised at 0°-5° with 10.5parts 4 N sodium nitrite solution. To the diazonium salt solution isadded 50 parts ice and enough sodium acetate to hold the pH at 3.5. Then4.7 parts 3-methylaniline are added and the mixture stirred at pH 3-3.5until no more diazonium salt is detectable. The dyestuff solution ismade alkaline with caustic soda, and the dyestuff which comes out ofsolution is separated and dissolved in 300 parts water and 20 parts 30%HCl.

The intermediate product is diazotised with 9 parts of 4 N sodiumnitrite solution at room temperature, and the diazo solution is addeddropwise to a suspension of 13.6 parts6-benzoylamino-1-naphthol-3-sulphonic acid in 500 parts of water,keeping the pH at 7-7.5. As soon as no more diazonium salt isdetectable, the blue-red dyestuff solution is treated with zinc chlorideto give a filterable suspension. By filtration and vacuum drying at 60°is obtained in powder form the dyestuff of the formula ##STR51## whichis soluble in acidic aqueous media and dyes paper in bordeaux redshades; the dyeings have good light- and wet-fastness.

Example 29

When 90 parts of the solution of Example (c) are used in place of the 67parts of the solution of Example (a) a dyestuff of formula ##STR52## isobtained, which dyes paper in blue-red shades, with good light- andwet-fastness properties.

Examples 30-47

Following the procedure of Example 28 and using the diazo, middle andterminal coupling components given in Table 3 below, disazo dyestuffsare obtained which dye paper in fast shades of the colours indicated.

                  TABLE 3                                                         ______________________________________                                                                      terminal                                                                      coupling                                        Example                                                                              Diazo     Middle       component                                       No.    Component Component    (see Table 2)                                                                          Colour                                 ______________________________________                                        30     D.sub.1c  aniline      K.sub.4  br                                     31     "         2-methoxyaniline                                                                           "        rv                                     32     "         "            K.sub.3  brv                                    33     D.sub.2c' 3-methylaniline                                                                            "        v                                      34     "         aniline      K.sub.1  v                                      35     D.sub.2c  2-methoxyaniline                                                                           "        br                                     36     D.sub.1a  3-methylaniline                                                                            K.sub.3  bbr                                    37     D.sub.2a  "            "        bbr                                    38a    D.sub.1a  "            K.sub.1  r                                      38b    "         "            K.sub.4  br                                     39     D.sub.2a  "            K.sub.1  r                                      40     D.sub.1b  "            " r                                             41     D.sub.2a  aniline      "        bo                                     42     D.sub.2b  "            "        r                                      43     D.sub.1a  "            "        bo                                     44     D.sub.1b  "            " bo                                            45     D.sub.3a  "            "        bo                                     46     D.sub.1a  2-methoxyaniline                                                                           "        rv                                     47     D.sub.2a  "            "        rv                                     ______________________________________                                    

Similarly, any other combinations of the diazo components listed inTable 1 with coupling components K₁ -K₄ and the middle components listedin Table 3 give disazo dyestuffs which dye paper in brown-red tored-violet or bordeaux red to brilliant blue-red shades, the dyeingshaving good fastness properties.

Example 48

3.15 Parts of a compound of formula ##STR53##

in which Z₃ is --NHCONH-- and the sulphonic acid groups are in the3,3'-positions are dispersed in 200 parts water. The solution obtainedin Example (c) (35.5 parts) is diazotised and added dropwise over 30minutes, keeping the pH at 7-8 by addition of sodium carbonate. After 1hour the product is filtered and dried in a vacuum at 60°, giving thedyestuff of the formula ##STR54##

which is soluble in acidic aqueous media and gives orange dyeings onpaper, having particularly good wet-fastness and very good fastness toalcohol.

Example 49

If, instead of 35.5 parts of the product of Example (c), 21.1 parts ofthe product of Example (a) is taken, a dyestuff is obtained having theformula ##STR55##

which is soluble in acidic aqueous media and gives orange dyeings onpaper, having good wet fastness, in particular good fastness to alcohol.

Examples 50-78

In manner analogous to Example 48, corresponding compounds may beprepared using a diazo component given in column 2 of Table 4 below anda coupling component of the formula given in Example 48, in which thebridging group Z₃ and the position of the sulphonic acid groups is givenin columns 3 and 4 of the Table. The colour of the dyeings obtained onpaper is indicated in column 5; such dyeings show good wet- andalcohol-fastness.

                                      TABLE 4                                     __________________________________________________________________________    Example                                                                            Diazo                  Position of                                       No.  Component                                                                             Z.sub.3        Sulfo Groups                                                                           Colour                                   __________________________________________________________________________    50   D.sub.1c                                                                              HNCOCHCHCONH   3,3'     ro                                       51   "                                                                                      ##STR56##     "        o                                        52   "                                                                                      ##STR57##     "        o                                        53   "                                                                                      ##STR58##     "        bo                                       54   "       HNCOC.sub.2 H.sub.4 CONH                                                                     "        o                                        55   "       NH             "        blr                                      56   D.sub.2c                                                                              NHCONH         "        o                                        57   "       "              4,4'     o                                        58   "                                                                                      ##STR59##     "        bo                                       59   D.sub.1c                                                                              "              3,3'     bor                                      60   "                                                                                      ##STR60##     "        bor                                      __________________________________________________________________________    Example                                                                            Diazo                  Position of                                       No.  component                                                                             Z.sub.3        SO.sub.3 H groups                                                                      Colour                                   __________________________________________________________________________    61   D.sub.1c                                                                              HNCOCHCHCONH   3,3'     rv                                       62   D.sub.2c                                                                              HNCONH         "        bor                                      63   "                                                                                      ##STR61##     "        br                                       64   "       HNCOC.sub.2 H.sub.4 CONH                                                                     "        blr                                      65   D.sub.4c                                                                              HNCOC.sub.2 H.sub.4 CONH                                                                     3,3'     o                                        66   "       HNCONH         "        o                                        67   D.sub.1b                                                                              "              "        o                                        68   D.sub.2a                                                                              "              "        o                                        69   D.sub.2a                                                                              "              4,4'     o                                        70   D.sub.3a                                                                              "              3,3'     o                                        71a  D.sub.1a                        o                                                     HNCOCHCHCONH   "                                                 71b  D.sub.2a                        o                                         72b72a                                                                             D.sub.2aD.sub.1a                                                                      ##STR62##     "         oo                                       73b73a                                                                             D.sub.2aD.sub.1a                                                                      ##STR63##     3,3'      roro                                     74b74a                                                                             D.sub.2aD.sub.1a                                                                      ##STR64##     "         roro                                    75a  D.sub.1a                        ro                                                    "              4,4'                                              75b  D.sub.2a                        ro                                       76a  D.sub.1a                        bbr                                                   NH             3,3'                                              76b  D.sub.1b                        bbr                                      77a  D.sub.1a                        o                                                     HNCOC.sub.2 H.sub.4 CONH                                                                     "                                                 77b  D.sub.1b                        o                                        78a  D.sub.2a                        o                                                     "              "                                                 78b  D.sub.2b                        o                                        __________________________________________________________________________

Analogous dyes with similar properties may be made using any of theabove-indicated coupling components with any of the diazo componentslisted in Table 1.

Example 79

6.2 Parts of 4-methoxyaniline are dissolved in 100 parts water and 25parts 30% HCl and cooled to 0°-5°. To the solution is added dropwise 50parts of 1 N sodium nitrite solution.

In a second reaction vessel is placed 140 parts by volume of thesolution prepared as in Example (d), and the above diazo solution isadded dropwise at pH 6-6.5. The mixture is stirred overnight, thentreated with 90 parts sodium chloride and 15 parts zinc chloride. Thedyestuff is filtered and vacuum dried at 60° to give a powder of formula##STR65##

which is soluble in acidic aqueous media and dyes paper in scarlet redshades, the dyeings having good light- and wet-fastness.

Examples 80-97

In manner analogous to Example 79, analogous monoazo compounds may beprepared using the diazo components and coupling components given inTable 5 below. The resulting compounds dye paper in the indicatedshades, the dyeings having good light- and wet-fastness.

                  TABLE 5                                                         ______________________________________                                        Example                   Coupling                                            No.     Diazo Component   Component  Colour                                   ______________________________________                                        80      4-methoxyaniline  K.sub.2d   sr                                       81a     2-methoxyaniline  K.sub.1d   ro                                       81b       "               K.sub.2d   ro                                       82a     1-amino-4-benzoylamino-                                                                         K.sub.1d   blr                                              benzene                                                               82b     1-amino-4-benzoylamino-                                                                         K.sub.2d   blr                                              benzene                                                               83a     1-amino-4-acetylamino-                                                                          K.sub.1d   blr                                              benzene                                                               83b     1-amino-4-acetylamino-                                                                          K.sub.2d   blr                                              benzene                                                               84a     4-aminodiphenylether                                                                            K.sub.1d   ro                                       84b       "               K.sub.2d   ro                                       85a     2,5-dimethoxyaniline                                                                            K.sub.1d   blr                                      85b       "               K.sub.2d   blr                                      86        "               K.sub.3d   blr                                      87a     2,5-dimethylaniline                                                                             K.sub.1d   o                                        87b       "               K.sub.2d   o                                        88a     2-methoxy-5-methylaniline                                                                       K.sub.1d   r                                        88b       "               K.sub.2d   r                                        89        "               K.sub.4d   r                                        90a     aniline           K.sub.1d   yo                                       90b       "               K.sub.2d   yo                                       91        "               K.sub.4d   yo                                       92a     3-chloro-4-methylaniline                                                                        K.sub.1d   o                                        92b       "               K.sub.2d   o                                        93      2-aminonaphthalene-                                                                             K.sub.1d   ro                                               sulfonamide                                                           94      4-methylaniline   K.sub.1d   o                                        95a     4-aminobenzanilide                                                                              K.sub.1d   yo                                       95b       "               K.sub.2d   yo                                       96      2-(4'-aminophenyl)-6-                                                                           K.sub.2d   ro                                               methylbenzothiazole                                                   97      2-aminodibenzofuran                                                                             K.sub.2d   o                                        ______________________________________                                    

Analogous compounds may be prepared by the use of the above diazocomponents with the other coupling components listed in Table 1.

Example 98

9.9 Part 4-aminoazobenzene are stirred overnight with 100 parts waterand 25 parts 30% HCl and diazotised by adding dropwise 50 parts of 1 Nsodium nitrite solution. In a second reaction vessel is placed 140 partsby volume of a solution containing 28 parts of the compound described inExample (d), together with 30 parts sodium acetate. The diazo solutionis added dropwise at pH 3-4, and the mixture is stirred overnight, thentreated with 50 parts 30% caustic soda to bring the pH to 8-9. Afterstirring for 1 hour, the precipitated dyestuff is filtered and dried togive a powder of the formula ##STR66##

which is soluble in acidic aqueous media and gives bluish-red dyeings onpaper which exhibit good light- and wet-fastness.

Examples 99-111

In manner analogous to Example 98 and using the diazo components, middlecomponents and terminal coupling components given in Table 6 below,corresponding dyestuffs are obtained which dye paper in the indicatedshades, the dyeings having good light- and wet-fastness.

                  TABLE 6                                                         ______________________________________                                                                       Terminal                                       Ex.               Middle       Coupling                                       No.  Diazo Component                                                                            Component    Component                                                                             Colour                                 ______________________________________                                         99               aniline      K.sub.2d                                                                              blr                                    100a  "             "          K.sub.3d                                                                              blr                                    100b   "            "          K.sub.4d                                                                              blr                                    101a   "          2-methoxyaniline                                                                           K.sub.1d                                                                              rv                                     101b   "            "          K.sub.2d                                                                              rv                                     102a   "          3-methylaniline                                                                            K.sub.1d                                                                              bor                                    102b   "            "          K.sub.2d                                                                              bor                                    103a 2,5-dimethoxy-                                                                             aniline      K.sub.1d                                                                              blr                                         aniline                                                                  103b 2,5-dimethoxy-                                                                               "          K.sub.2d                                                                              blr                                         aniline                                                                  104a 4-methylaniline                                                                              "          K.sub.1d                                                                              blr                                    104b   "            "          K.sub.2d                                                                              blr                                    105a   "            "          K.sub.3d                                                                              blr                                    105b   "            "          K.sub.4d                                                                              blr                                    106a   "          2-methoxyaniline                                                                           K.sub.1d                                                                              rv                                     106b   "            "          K.sub.2d                                                                              rv                                     107a 1-amino-4-acetyl-                                                             aminobenzene aniline      K.sub.1d                                                                              blr                                    107b 1-amino-4-acetyl-                                                                            "          K.sub.2d                                                                              blr                                         aminobenzene                                                             108a 3-chloro-4-methyl-                                                                         3-methylaniline                                                                            K.sub.1d                                                                              br                                          aniline                                                                  108b 3-chloro-4-methyl-                                                                           "          K.sub.2d                                                                              br                                          aniline                                                                  109a 3-aminobenzene-                                                                            2-methoxyaniline                                                                           K.sub.1d                                                                              v                                           sulfonamide                                                              109b 3-aminobenzene-                                                                              "          K.sub.2d                                                                              v                                           sulfonamide                                                              110a 3-aminobenzamide                                                                           aniline      K.sub.1d                                                                              blr                                    110b   "            "          K.sub.2d                                                                              blr                                    111a 3-aminophenyl-                                                                               "          K.sub.1d                                                                              blr                                         methylsulfone                                                            111b 3-aminophenyl-                                                                               "          K.sub.2d                                                                              blr                                         methylsulfone                                                            ______________________________________                                    

Analogous compounds may be prepared using the diazo and middlecomponents listed in Table 6 with the remaining coupling componentslisted in Table 1.

Example 112

A diazo solution is prepared by adding 27 parts of a 4 N sodium nitritesolution dropwise to a suspension of 15 parts 3-aminoacetanilide in 100parts water and 25 parts 30% HCl at 0°-5°. This diazo solution is pouredinto a mixture of 60 parts of the solution prepared in Example (d), 200parts water and 100 parts ice, holding the pH at 3-3.5 by dropwiseaddition of 70 parts 4 N sodium carbonate solution. After 2 hours 45parts 65% sulphuric acid are added and the mixture is stirred for 3hours at 85°, by which time the cleavage of the acetyl group ispractically complete. The solution is cooled to room temperature andtreated with 15 parts zinc chloride and, after 10 minutes, 60 partscommon salt.

The resulting dyestuff is filtered off, stirred in 300 parts water and20 parts 30% HCl and diazotised with 25 parts of 4 N sodium nitritesolution. The diazo solution is then added to 60 parts of the solutionprepared as in Example (d), 300 parts water and 100 parts ice, at a pHof 4-4.5. When coupling is complete, the solution is made alkaline withcaustic soda, and the precipitated dyestuff filtered and dried. Theresulting compound has the formula ##STR67## has good solubility inacidic aqueous media and dyes paper in orange shades having excellentwet- and alcohol-fastness.

Example 113

10.6 Parts 4,4'-diaminodibenzyl are dissolved in 300 parts water and 25parts 30% HCl, cooled to 0°-5° and tetraazotised with 27 parts 4 Nsodium nitrite. The mixture is treated with aminosulphonic acid todestroy residual nitrous acid, and the tetraazo solution is poured intoa mixture of 60 parts of the product of Example (d), 700 parts water and75 parts salt, keeping the pH at 4-5 by addition of ˜50 parts sodiumacetate. After coupling the dyestuff was precipitated with caustic soda,filtered and dried. The resulting dyestuff, of the formula ##STR68## hasgood solubility in acidic aqueous media, and gives on paper red-orangedyeings having extremely good wet- and alcohol-fastness.

Examples 114-128

In manner analogous to Example 113, corresponding dyestuffs are producedfrom the diamines and coupling components listed in Table 7 below. Theresulting dyestuffs give dyeings on paper of the shades indicated,having good wet fastness and particularly good fastness to alcohol.

                                      TABLE 7                                     __________________________________________________________________________    Example                                                                       No.  Tetraazo Component      Coupling Component                                                                       Colour                                __________________________________________________________________________    114a                                                                                ##STR69##              K.sub.1d   ro                                    114b    "                    K.sub.2d   ro                                    115a                                                                                ##STR70##              "          ro                                    115b    "                    "          ro                                    116a                                                                                ##STR71##              "          yo                                    116b    "                    "          yo                                    117                                                                                 ##STR72##              K.sub.2d   ro                                    118     "                    K.sub.4d   ro                                    119a                                                                                ##STR73##              K.sub.1d   ro                                    119b    "                    K.sub.2d   ro                                    120a                                                                                ##STR74##              K.sub.1d   yo                                    120b    "                    K.sub.2d   yo                                    121a                                                                                ##STR75##              K.sub.1d   blr                                   121b    "                    K.sub.2d   blr                                   122a                                                                                ##STR76##              K.sub.1d   yo                                    122b    "                    K.sub.2d   yo                                    123a                                                                                ##STR77##              K.sub.1d   o                                     123b    "                    K.sub.2d   o                                     124a                                                                                ##STR78##              K.sub.1d   o                                     124b    "                    K.sub.2d   o                                     125a                                                                                ##STR79##              K.sub.1d   r                                     125b    "                    K.sub.2d   r                                     126a                                                                                ##STR80##              K.sub.1d   or                                    126b    "                    K.sub.2d   or                                    127a                                                                                ##STR81##              K.sub.1d   o                                     127b    "                    K.sub.2d   o                                     128a                                                                                ##STR82##              K.sub. 1d  v                                     128b    "                    K.sub.2d   v                                     __________________________________________________________________________

Analogous dyestuffs may be prepared using the other coupling componentslisted in Table 1.

Example 129

45 Parts of the dyestuff of Example 98 are dissolved in 500 parts watercontaining 3.4 parts glacial acetic acid. The resulting solution isevaporated to dryness, giving the dyestuff salt of the formula ##STR83##

which has high solubility in cold water. Similarly, hydrochloric,sulphuric, phosphoric, formic and lactic acids may be used instead ofacetic acid to give corresponding salts. The dyestuffs of the otherexamples may similarly be converted to salt forms.

Example 130

80 Parts of the dyestuff salt of Example 129 are added to a solution of20 parts dextrin and 20 parts glacial acetic acid in 500 parts water,and stirred to give a homogeneous suspension. Spray drying procedures ablue-red granulate which is very soluble in water and which dyes paperin bluish-red shades.

The salt forms of the dyestuffs of the other examples may be convertedto granulates in similar manner.

Example 131

120 Parts of the dyestuff salt of Example 129 are added to a mixture of150 parts butylpolyglycol, 50 parts glacial acetic acid and 600 partswater, and dissolved by warming to 60°. The solution is filtered, cooledto room temperature and made up to 1000 parts with water. The resultingdye concentrate solution is storable for several months at roomtemperature and may be used directly or after dilution with water fordyeing paper in bluish-red shades.

Salts of the dyestuffs of the other examples may be similarly worked upinto stable liquid dye preparations.

Application Example A

70 Part of chemically bleached sulphite cellulose obtained from pinewoodand 30 parts of chemically bleached sulphite cellulose obtained frombirchwood are ground in 2000 part of water in a Hollander. 0.5 Part ofthe dyestuff from Example 36 (as an acid addition salt, e.g. accordingto Example 129) are sprinkled into this pulp. Paper is produced fromthis pulp after mixing for 20 minutes. The absorbent paper which isobtained in this manner is dyed in a bluish-red shade. The waste wateris practically colourless.

Application Example B

0.5 Part of the dyestuff from Example 98 (as an acid addition salt, e.g.according to Example 129) are dissolved in 100 parts of hot water andcooled to room temperature. This solution is added to 100 parts ofchemically bleached sulphite cellulose which have been ground in aHollander with 2000 parts of water. Sizing takes place after thoroughmixing for 15 minutes. The paper which is produced from this materialhas a bluish-red shade and good light- and wet-fastness.

Application Example C

An absorbent length of unsized paper is drawn at 40°-50° through adyestuff solution having the following composition:

0.5 parts of the dyestuff from Example 36 (as an acid addition salt,e.g. according to Example 129)

0.5 parts of starch and

99.0 parts of water.

The excess dyestuff solution is squeezed out through two rollers. Thedried length of paper is dyed in a bluish-red shade.

The dyestuffs of the remaining Examples may also be used for dyeingaccording to Application Examples A-C.

Application Example D

100 Parts freshly tanned and neutralised chrome leather are agitated for30 minutes in a vessel with a dyebath of 250 parts water at 55° and 0.5part of the dyestuff of Example 98 in acid addition salt form, and thentreated in the same bath for 30 minutes with 2 parts of an anionic fattyliquor based on sulphonated train oil. The leather is then dried andprepared in the normal way, giving a leather evenly dyed in a bluish-redshade.

Other low affinity vegetable-tanned leathers can similarly be dyed byknown methods.

Application Example E

2 Parts of the dyestuff of Example 98 in acid addition salt form aredissolved in 4000 parts demineralised water at 40°. 100 Parts of acotton textile substrate are added, and the bath is raised to boilingpoint over 30 minutes and held at the boil for 1 hour. After rinsing anddrying, a bluish-red dyeing is obtained having good light- andwet-fastness. The dye exhausts practically quantitatively, and the wastewater is almost colourless.

What is claimed is:
 1. A compound of the formula ##STR84## or anexternal salt thereof, wherein each R₁ is independently hydrogen or C₁₋₄alkyl,R₈ is hydrogen, C₁₋₄ alkyl, C₁₋₄ alkoxy, halo, C₁₋₄ alkylamino,di-(C₁₋₄ alkyl)amino, --SO₂ NR₁ R₁ or --CONR₁ R₁,wherein each R₁ isindependently hydrogen or C₁₋₄ alkyl, R₉ is hydrogen, halo, C₁₋₄ alkyl,C₁₋₄ alkoxy, phenoxy, --NHCOR₁₄, --SO₂ R₁₄, --SO₂ NR₁ R₁ or --CONR₁R₁,wherein each R₁ is independently hydrogen or C₁₋₄ alkyl, and R₁₄ isC₁₋₄ alkyl or phenyl, R₁₀ is hydrogen, halo, C₁₋₄ alkyl or C₁₋₄ alkoxy,R₁₃ is hydrogen; amino; (C₁₋₄ alkyl)carbonylamino; benzamido;substituted benzamido having, on the phenyl ring, 1 or 2 substituentsselected from halo, nitro, amino, C₁₋₄ alkyl and C₁₋₄ alkoxy; or##STR85## wherein R₁ is hydrogen or C₁₋₄ alkyl, Y is chloro, hydroxy,amino or an amino group having at least one aliphatic, cycloaliphatic oraromatic substituent, andY' is hydroxy, amino or an amino group havingat least one aliphatic, cycloaliphatic or aromatic substituent, eachT_(a) is independently -NR₂ '-Q-NR₃ 'R₄ ' or -NR₂ '-Q-N.sup.⊕ R₅ 'R₆ 'R₇', wherein R₂ ' is hydrogen or methyl,each of R₃ ' and R₄ ' isindependently hydrogen, C₁₋₆ alkyl, n-C₂₋₃ -hydroxyalkyl or benzyl, eachof R₅ ' and R₆ ' is independently C₁₋₆ alkyl, n-C₂₋₃ hydroxyalkyl orbenzyl or R₃ ' and R₄ ' or R₅ ' and R₆ ' taken together and with thenitrogen atom to which they are joined form a pyrrolidine, piperidine ormorpholine ring, R₇ ' is methyl, ethyl or benzyl, and Q is linear orbranched C₂₋₆ alkylene, each T_(Ia) is independently --CO--T_(a) or--SO₂ --T_(a),wherein T_(a) is as defined above, each Y is independentlychloro, hydroxy, amino or an amino group having at least one aliphatic,cycloaliphatic or aromatic substituent, m is 1 or 2, n is 0, 1, 2, 3 or4, and p is 0, 1, 2 or 3, with the proviso that n+2p≧m+1,with theprovisos that (i) each basic group is independently in free base,internal salt or acid addition salt form, (ii) the positive charge ofeach cationic group is independently balanced by the negative charge ofa --SO₃.sup.⊖ group of the molecule or an external non-chromophoricanion, and (iii) the number of basic groups in internal salt form andcationic groups the positive charge of which is balanced by the negativecharge of a --SO₃.sup.⊖ group of the molecule does not exceed the numberof sulfo groups present in the molecule.
 2. A compound according toclaim 1 having the formula ##STR86## or an external salt thereof,wherein R₈ is hydrogen, C₁₋₄ alkyl, C₁₋₄ alkoxy, halo, C₁₋₄ -alkylamino,di-(C₁₋₄ alkyl)amino, --SO₂ NR₁ R₁ or --CONR₁ R₁,wherein each R₁ isindependently hydrogen or C₁₋₄ alkyl, R₁₃ is hydrogen; amino; (C₁₋₄alkyl)carbonylamino; benzamido; substituted benzamido having, on thephenyl ring, 1 or 2 substituents selected from halo, nitro, amino, C₁₋₄alkyl and C₁₋₄ alkoxy; ##STR87## wherein R₁ is hydrogen or C₁₋₄ alkyl, Yis chloro, hydroxy, amino or an amino group having at least onealiphatic, cycloaliphatic or aromatic substituent, and Y' is hydroxy,amino or an amino group having at least one aliphatic, cycloaliphatic oraromatic substituent, and each T_(Ia) is independently --CO--T_(a) or--SO₂ --T_(a),wherein T_(a) is --NR₂ '--Q--NR₃ 'R₄ ' or --NR₂'--Q--N.sup.⊕ R₅ 'R₆ 'R₇ ',wherein R₂ ' is hydrogen or methyl, each ofR₃ ' and R₄ ' is independently hydrogen, C₁₋₆ alkyl, n-C₂₋₃-hydroxyalkyl or benzyl, each of R₅ ' and R₆ ' is independently C₁₋₆alkyl, n-C₂₋₃ -hydroxyalkyl or benzyl or R₃ ' and R₄ ' or R₅ ' and R₆ 'taken together and with the nitrogen atom to which they are joined forma pyrrolidine, piperidine or morpholine ring, R₇ ' is methyl, ethyl orbenzyl, and Q is linear or branched C₂₋₆ alkylene,with the provisos that(i) each basic group is independently in free base, internal salt oracid addition salt form, (ii) the positive charge of each cationic groupis independently balanced by the negative charge of the --SO₃.sup.⊖group of the molecule or an external non-chromophoric anion, and (iii)the maximum number of basic groups in internal salt form and cationicgroups the positive charge of which is balanced by the negative chargeof the --SO₃.sup.⊖ group of the molecule is one.
 3. A compound accordingto claim 2, or an external salt thereof,wherein each of R₃ ' and R₄ ' isindependently hydrogen, C₁₋₆ alkyl, n-C₂₋₃ hydroxyalkyl or benzyl, eachof R₅ ' and R₆ ' is independently C₁₋₆ alkyl, n-C₂₋₃ -hydroxyalkyl orbenzyl or R₃ ' and R₄ ' or R₅ ' and R₆ ' taken together and with thenitrogen atom to which they are joined are pyrrolidino, piperidino ormorpholino, Y is chloro, hydroxy, --NR₂₁ R₂₂, C₅₋₆ -cycloalkylamino,anilino or substituted anilino having, on the phenyl ring, 1 or 2substituents selected from halo, C₁₋₄ -alkyl, C₁₋₄ alkoxy, hydroxy andphenoxy, wherein each of R₂₁ and R₂₂ is independently hydrogen, C₁₋₄alkyl or C₁₋₄ alkyl substituted by chloro, bromo, phenyl or hydroxy, andY' is hydroxy, --NR₂₁ R₂₂, C₅₋₆ cycloalkylamino, anilino or substitutedanilino having, on the phenyl ring, 1 or 2 substituents selected fromhalo, C₁₋₄ alkyl, C₁₋₄ alkoxy, hydroxy and phenoxy,wherein each of R₂₁and R₂₂ is independently hydrogen, C₁₋₄ alkyl or C₁₋₄ alkyl substitutedby chloro, bromo, phenyl or hydroxy.
 4. A compound according to claim 3,or an external salt thereof,wherein each T_(Ia) is independently--CO--X_(a) or --SO₂ --X_(a),wherein X_(a) is --NR₂ '--Q--NR₃ 'R₄',wherein R₂ ' is hydrogen or methyl, each of R₃ ' and R₄ ' isindependently hydrogen, C₁₋₆ alkyl, n-C₂₋₃ -hydroxyalkyl or benzyl or R₃' and R₄ ' taken together and with the nitrogen atom to which they arejoined are pyrrolidino, piperidino or morpholino, and Q is linear orbranched C₂₋₆ alkylene.
 5. A compound according to claim 4, or anexternal salt thereof,wherein the two T_(Ia) 's are identical.
 6. Acompound according to claim 5 having the formula ##STR88## or anexternal salt thereof, wherein R₈ ' is hydrogen, methyl, methoxy orchloro,R₁₃ ' is hydrogen, amino, acetamido or benzamido, and each X_(Ib)is --CO--X_(b) or --SO₂ --X_(b),wherein X_(b) is --NR₂ '--Q--NR₃ "R₄",wherein R₂ ' is hydrogen or methyl, each of R₃ " and R₄ " isindependently hydrogen, C₁₋₄ alkyl or hydroxyethyl or R₃ " and R₄ "taken together and with the nitrogen atom to which they are joined arepiperidino or morpholino, and Q is linear or branched C₂₋₆ alkylene,with the provisos that the two X_(Ib) 's are identical and are in the2,5- or 3,5-positions,with the proviso that each basic group isindependently in free base, internal salt (maximum of one) or acidaddition salt form.
 7. A compound according to claim 6, or an externalsalt thereof,wherein each X_(Ib) is --CO--NR₂ '--(CH₂)_(s) --NR₃ "R₄",wherein R₂ ' is hydrogen or methyl, each of R₃ " and R₄ " isindependently hydrogen, C₁₋₄ alkyl or hydroxyethyl or R₃ " and R₄ "taken together and with the nitrogen atom to which they are joined arepiperidino or morpholino, and s is 2 to 6, inclusive.
 8. A compoundaccording to claim 7, or an external salt thereof,wherein R₈ ' ishydrogen, and each X_(Ib) is --CO--NR₂ '--(CH₂)_(t) --NR₃ "'R₄"',wherein R₂ ' is hydrogen or methyl, each of R₃ "' and R₄ "' isindependently methyl or ethyl, and t is 2 or
 3. 9. A compound accordingto claim 8, or an external salt thereof, wherein R₂ ' is hydrogen.
 10. Acompound according to claim 9 having the formula ##STR89##
 11. Anexternal salt according to claim 3 having the formula ##STR90## whereinR₁₃ ' is hydrogen, amino, acetamido or benzamido, and each X_(Ie) is--CO--NR₂ '--(CH₂)_(t) --N.sup.⊕ (CH₃)₃,wherein R₂ ' is hydrogen ormethyl, and t is 2 or 3,with the proviso that the positive charge ofeach cationic group is independently balanced by the negative charge ofthe --SO₃.sup.⊖ group of the molecule (maximum of one) or an externalnon-chromophoric anion.
 12. An external salt according to claim 11wherein each R₂ ' is hydrogen.
 13. A compound according to claim 1having the formula ##STR91## or an external salt thereof, wherein eachR₁ is independently hydrogen or C₁₋₄ alkyl,R₉ is hydrogen, halo, C₁₋₄alkyl, C₁₋₄ alkoxy, phenoxy, --NHCOR₁₄, --SO₂ R₁₄ --SO₂ NR₁ R₁ or--CONR₁ R₁,wherein each R₁ is independently hydrogen or C₁₋₄ alkyl, andR₁₄ is C₁₋₄ alkyl or phenyl, R₁₀ is hydrogen, halo, C₁₋₄ alkyl or C₁₋₄alkoxy, R₁₃ is hydrogen; amino; (C₁₋₄ alkyl)carbonylamino; benzamido;substituted benzamido having, on the phenyl ring, 1 or 2 substituentsselected from halo, nitro, amino, C₁₋₄ alkyl and C₁₋₄ alkoxy; or##STR92## wherein R₁ is hydrogen or C₁₋₄ alkyl, Y is chloro, hydroxy,amino or an amino group having at least one aliphatic, cycloaliphatic oraromatic substituent, andY' is hydroxy, amino or an amino group havingat least one aliphatic, cycloaliphatic or aromatic substituent, eachT_(a) is independently --NR₂ '--Q--NR₃ 'R₄ ' or --NR₂ '--Q--N.sup.⊕ R₅'R₆ 'R₇ ',wherein R₂ ' is hydrogen or methyl, each of R₃ ' and R₄ ' isindependently hydrogen, C₁₋₆ alkyl, n-C₂₋₃ hydroxyalkyl or benzyl, eachof R₅ ' and R₆ ' is independently C₁₋₆ alkyl, n-C₂₋₃ hydroxyalkyl orbenzyl or R₃ ' and R₄ ' or R₅ ' and R₆ ' taken together and with thenitrogen atom to which they are joined form a pyrrolidine, piperidine ormorpholine ring, R₇ ' is methyl, ethyl or benzyl, and Q is linear orbranched C₂₋₆ alkylene, each Y is independently chloro, hydroxy, aminoor an amino group having at least one aliphatic, cycloaliphatic oraromatic substituent, m is 1 or 2, n is 0, 1, 2, 3 or 4, and p is 0, 1,2 or 3, with the proviso that n+2p≧m+1,with the provisos that (i) eachbasic group is independently in free base, internal salt or acidaddition salt form, (ii) the positive charge of each cationic group isindependently balanced by the negative charge of a --SO₃.sup.⊖ group ofthe molecule or an external non-chromophoric anion, and (iii) the numberof basic groups in internal salt form and cationic groups the positivecharge of which is balanced by the negative charge of a --SO₃.sup.⊖group of the molecule does not exceed the number of sulfo groups presentin the molecule.
 14. A compound according to claim 13, or an externalsalt thereof,wherein each of R₃ ' and R₄ ' is independently hydrogen,C₁₋₆ alkyl, n-C₂₋₃ hydroxyalkyl or benzyl, each of R₅ ' and R₆ ' isindependently C₁₋₆ alkyl, n-C₂₋₃ hydroxyalkyl or benzyl or R₃ ' and R₄ 'or R₅ ' and R₆ ' taken together and with the nitrogen atom to which theyare joined are pyrrolidino, piperidino or morpholino, each Y isindependently chloro, hydroxy, --NR₂₁ R₂₂, C₅₋₆ cycloalkylamino, anilinoor substituted anilino having, on the phenyl ring, 1 or 2 substituentsselected from halo, C₁₋₄ alkyl, C₁₋₄ alkoxy, hydroxy and phenoxy,whereineach of R₂₁ and R₂₂ is independently hydrogen, C₁₋₄ alkyl or C₁₋₄ alkylsubstituted by chloro, bromo, phenyl or hydroxy, and Y' is hydroxy,--NR₂₁ R₂₂, C₅₋₆ cycloalkylamino, anilino or substituted anilino having,on the phenyl ring, 1 or 2 substituents selected from halo, C₁₋₄ alkyl,C₁₋₄ alkoxy, hydroxy and phenoxy,wherein each of R₂₁ and R₂₂ isindependently hydrogen, C₁₋₄ alkyl or C₁₋₄ alkyl substituted by chloro,bromo, phenyl or hydroxy.
 15. A compound according to claim 14, or anexternal salt thereof,wherein each T_(a) is independently --NR₂'--Q--NR₃ 'R₄ ', wherein R₂ ' is hydrogen or methyl, each of R₃ ' and R₄' is independently hydrogen, C₁₋₆ alkyl, n-C₂₋₃ hydroxyalkyl or benzylor R₃ ' and R₄ ' taken together and with the nitrogen atom to which theyare joined are pyrrolidino, piperidino or morpholino, and Q is linear orbranched C₂₋₆ alkylene.
 16. A compound according to claim 14 having theformula ##STR93## or an external salt thereof, wherein R₁ ' is hydrogenor methyl,R₉ ' is hydrogen, chloro, methyl, methoxy, acetamido,benzamido, sulfamoyl or carbamoyl, R₁₃ ' is hydrogen, amino, acetamidoor benzamido, and each T_(b) is independently --NR₂ '--Q--NR₃ "R₄ " or--NR₂ '--Q--N.sup.⊕ R₅ "R₆ "R₇ ',wherein R₂ ' is hydrogen or methyl,each of R₃ " and R₄ " is independently hydrogen, C₁₋₄ alkyl orhydroxyethyl, each of R₅ " and R₆ " is independently C₁₋₄ alkyl orhydroxyethyl or R₃ " and R₄ " or R₅ " and R₆ " taken together and withthe nitrogen atom to which they are joined are piperidino or morpholino,R₇ ' is methyl, ethyl or benzyl, and Q is linear or branched C₂₋₆alkylene,with the provisos that (i) each basic group is independently infree base, internal salt or acid addition salt form, (ii) the positivecharge of each cationic group is independently balanced by the negativecharge of the --SO₃.sup.⊖ group of the molecule or an externalnon-chromophoric anion, and (iii) the maximum number of basic groups ininternal salt form and cationic groups the positive charge of which isbalanced by the negative charge of a --SO₃.sup.⊖ group of the moleculeis one.
 17. A compound according to claim 16,or an external saltthereof, wherein each T_(b) is independently --NR₂ '--Q--NR₃ "R₄ ",wherein R₂ ' is hydrogen or methyl,each of R₃ " and R₄ " isindependently hydrogen, C₁₋₄ alkyl or hydroxyethyl or R₃ " and R₄ "taken together and with the nitrogen atom to which they are joined arepiperidino or morpholino, and Q is linear or branched C₂₋₆ alkylene. 18.A compound according to claim 17, or an external salt thereof,wherein R₉' is hydrogen, chloro, methyl, methoxy, acetamido or benzamido, and eachT_(b) is independently --NR₂ '--(CH₂)_(s) --NR₃ "R₄ ",wherein R₂ ' ishydrogen or methyl, each of R₃ " and R₄ " is independently hydrogen,C₁₋₄ alkyl or hydroxyethyl or R₃ " and R₄ " taken together and with thenitrogen atom to which they are joined are piperidino or morpholino, ands is 2 to 6, inclusive.
 19. A compound according to claim 18, or anexternal salt thereof,wherein R₉ ' is hydrogen, and each T_(b) isindependently --NR₂ '--(CH₂)_(t) --NR₃ "'R₄ "',wherein R₂ ' is hydrogenor methyl, each of R₃ "' and R₄ "' is independently methyl or ethyl, andt is 2 or
 3. 20. A compound according to claim 19, or an external saltthereof,wherein R₁ ' is hydrogen, and each R₂ ' is hydrogen.
 21. Thecompound according to claim 20 having the formula ##STR94##
 22. Anexternal salt according to claim 16wherein R₉ ' is hydrogen, and eachT_(b) is independently --NR₂ '--(CH₂)_(t) --N.sup.⊕ (CH₃)₃,wherein R₂ 'is hydrogen or methyl, and t is 2 or
 3. 23. An external salt accordingto claim 22 wherein each R₂ ' is hydrogen.
 24. A compound according toclaim 14 having the formula ##STR95## or an external salt thereof,wherein R₁ ' is hydrogen or methyl,R₉ ' is hydrogen, chloro, methyl,methoxy, acetamido, benzamido, sulfamoyl or carbamoyl, R₁₀ ' ishydrogen, chloro, methyl or methoxy, and each T_(b) is independently--NR₂ '--Q--NR₃ "R₄ " or --NR₂ '--Q--N.sup.⊕ R₅ "R₆ "R₇ ',wherein R₂ 'is hydrogen or methyl, each of R₃ " and R₄ " is independently hydrogen,C₁₋₄ alkyl or hydroxyethyl, each of R₅ " and R₆ " is independently C₁₋₄alkyl or hydroxyethyl or R₃ " and R₄ " or R₅ " and R₆ " taken togetherand with the nitrogen atom to which they are joined are piperidino ormorpholino, and Q is linear or branched C₂₋₆ alkylene,with the provisosthat (i) each basic group is independently in free base, internal saltor acid addition salt form, (ii) the positive charge of each cationicgroup is independently balanced by the negative charge of the--SO₃.sup.⊖ group of the molecule or an external non-chromophoric anion,and (iii) the maximum number of basic groups in internal salt form andcationic groups the positive charge of which is balanced by the negativecharge of the --SO₃.sup.⊖ group of the molecule is one.
 25. A compoundaccording to claim 24, or an external salt thereof,wherein each T_(b) isindependently --NR₂ '--Q--NR₃ "R₄ ",wherein R₂ ' is hydrogen or methyl,each of R₃ " and R₄ " is independently hydrogen, C₁₋₄ alkyl orhydroxyethyl or R₃ " and R₄ " taken together and with the nitrogen atomto which they are joined are piperidino or morpholino, and Q is linearor branched C₂₋₆ alkylene.
 26. A compound according to claim 25, or anexternal salt thereof,wherein R₉ ' is hydrogen, chloro, methyl, methoxy,acetamido or benzamido, R₁₀ ' is hydrogen, and each T_(b) isindependently --NR₂ '--(CH₂)_(s) --NR₃ "R₄ ",wherein R₂ ' is hydrogen ormethyl, each of R₃ " and R₄ " is independently hydrogen, C₁₋₄ alkyl orhydroxyethyl or R₃ " and R₄ " taken together and with the nitrogen atomto which they are joined are piperidino or morpholino, and s is 2 to 6,inclusive.
 27. A compound according to claim 26, or an external saltthereof,wherein each T_(b) is independently --NR₂ '--(CH₂)_(t) --NR₃"'R₄ "',wherein R₂ ' is hydrogen or methyl, each of R₃ "' and R₄ "' isindependently methyl or ethyl, and t is 2 or
 3. 28. A compound accordingto claim 27, or an external salt thereof,wherein R₁ ' is hydrogen, andeach R₂ ' is hydrogen.
 29. The compound according to claim 28 having theformula ##STR96##
 30. An external salt according to claim 24wherein R₉ 'is hydrogen, chloro, methyl, methoxy, acetamido or benzamido, R₁₀ ' ishydrogen, and each T_(b) is independently --NR₂ '--(CH₂)_(t) --N.sup.⊕(CH₃)₃,wherein R₂ ' is hydrogen or methyl, and t is 2 or
 3. 31. Anexternal salt according to claim 30 wherein each R₂ ' is hydrogen.
 32. Amethod of dyeing a cellulosic substrate comprising applying thereto acompound according to claim 1, or an external salt thereof.
 33. A methodof dyeing leather comprising applying thereto a compound according toclaim 1, or an external salt thereof.